Floral ontogeny and systematic position of the Didiereaceae

Floral ontogenetical data from all four genera of the Didiereaceae (s.str.) are presented for the first time. All Didiereaceae s.str. are dioecious, having unisexual flowers with organ rudiments of the opposite sex. Two median bracts followed by a tetramerous perianth (two alternating dimerous ``whorls'), a slightly complex androecium with 6–12 stamens in a single row (on a common ring primordium), four of which mostly alternating with the perianth members, and one basal ovule connecting three free septa at their very base are flower characters in Didiereaceae, supporting phylogenetic analyses based on nucleotide sequence data. Closest relatives are the (formerly) portulacaceous genera Portulacaria (5 stamens alternating with the perianth), Ceraria (5 stamens alternating with the perianth), and Calyptrotheca (many stamens), all with pentamerous perianths, from which the tetramerous perianth in Didiereaceae can be derived. Applequist and Wallace (2003) included these three genera in an expanded family Didiereaceae (with three subfamilies).     

Small but not ephemeral: newly discovered species of Aphelinidae and Trichogrammatidae (Insecta: Hymenoptera: Chalcidoidea) from Eocene amber

New species of fossil Aphelinidae and Trichogrammatidae are described from middle Eocene (Lutetian) Baltic amber (41.3–47.8 Ma). A new subfamily, two new genera and three new species of Aphelinidae are described, with comments on their placement: Phtuaria fimbriae gen.n. , sp.n. in Phtuariinae subf.n. , Glaesaphytis interregni gen.n. , sp.n. and Centrodora brevispinae sp.n. These represent the first described true fossil Aphelinidae. Four new species of Trichogrammatidae are described: Mirufens illusionis sp.n. , Palaeogramma eos gen.n. , sp.n. , Pterandrophysalis plasmans sp.n. and Szelenyia terebrae sp.n. , thus expanding our knowledge of fossil Trichogrammatidae beyond the single previously described species. The presence of recognizable extant genera of Aphelinidae and Trichogrammatidae in the Eocene suggests that the morphology of these genera has been relatively invariant despite highly variable conditions during and since the Eocene. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:E9AD60B6‐3D56‐4E74‐AA54‐F7B91F4FDC79 .     

Diversity of Alticinae in Oaxaca,Mexico: A preliminary study (Coleoptera,Chrysomelidae)

This is a preliminary study of the diversity of the Flea Beetles (Alticinae) of the Mexican state of Oaxaca based on fieldwork by the author in 1991, 1997, and 2010, the literature, and specimens in several institutional collections. The number of genera and species for Mexico as well as for Oaxaca increased significantly from previous studies. There are now 625 species in 90 genera recorded from Mexico with 275 species in 68 genera recorded from Oaxaca. There are 113 species known only from the state of Oaxaca and another 38 species known only from Oaxaca and the surrounding states. Oaxaca has a relatively high diversity as well as a high percentage of endemism. This study also demonstrates the effects of how even a small amount of fieldwork together with extracting specimen data from institutional collections can significantly increase the total faunistic and diversity knowledge of an area. A complete list of the genera and species known from Oaxaca is included.     

Phylogeny and classification of the Signiphoridae (Hymenoptera: Chalcidoidea)

Abstract. A data set consisting of twenty-eight anatomical characters scored for twenty-eight terminal taxa representing the world fauna of Signiphoridae was analysed using parsimony and compatibility methods. The Coccophaginae (Aphelinidae) and the Azotinae (Aphelinidae) were used as outgroups to establish polarity of character state changes. Relationships of Signiphoridae to other Chalcidoidea are discussed. Several multistate characters were treated in the parsimony analyses either as unordered or as ordered into transformation series using additive binary coding, which in some cases drastically reduced the number of equally parsimonious solutions. Monophyly of Signiphoridae is supported by seven synapomorphies. Four genera, Chartocerus, Thysanus, Clytina and Signiphora , are recognized within Signiphoridae based on synapomorphies. Rozanoviella syn.n . and Kerrichiella syn.n . are synonymized under Signiphora. Species of Signiphora are further assigned to four species groups, three of which are demonstrably monophyletic. Nine species or subspecies are transferred to Chartocerus from Signiphora ( australicus comb.n. , australiensis comb.n. , australiensis orbiculatus comb.n., beethoveni comb.n. , corvinus comb.n. , funeralis comb.n. , reticulata comb.n. , ruskini comb.n. , thusanoides comb.n.) , one species to Thysanus from Signiphora (melancholicus comb.n.) , and one species to Signiphora from Kerrichiella ( coleoptratus comb.n.) . A key to genera of Signiphoridae and species groups of Signiphora is presented. A diagnosis, relevant nomenclatural history, and a list of included species are given for each genus and species group, and the biology and distribution of each is summarized.     

Intracellular distribution and late endosomal effects of the ocular albinism type 1 gene product: consequences of disease-causing mutations and implications for melanosome biogenesis

To investigate the function of ocular albinism type 1 ( OA1 ), the gene responsible for X-linked ocular albinism, we employed a construct containing murine Oa1 fused to green fluorescent protein (GFP) in a heterologous COS cell expression system. The cellular distribution of wild-type (WT) Oa1 protein and Oa1 proteins reflecting mutations causing X-linked ocular albinism were examined. Comparison with different organelle markers revealed that Oa1-GFP localized to the late endolysosomal compartments. Some Oa1 mutant proteins failed to exit the endoplasmic reticulum (ER) (Class I mutants), while other mutants partially (Class II mutants) or fully (Class III mutants) exited the ER and trafficked to endolysosomal compartments. We observed that expression of WT Oa1-GFP in COS cells caused an apparent enlargement of late endosomes and a redistribution of the mannose-6-phosphate receptor (M6PR). None of the mutants displayed the full range of effects on the redistribution of M6PR exhibited by WT Oa1. The effects of Oa1 on late endosome structure and content are thus likely to reflect an important biological property of Oa1. We propose that OA1 is involved in reorganizing the endolysosomal compartment as a necessary step in ocular melanosome biogenesis.     

The ocular albinism type 1 gene product is an N-glycoprotein but glycosylation is not required for its subcellular distribution.

The ocular albinism type 1 (OA1) gene product is a membrane glycoprotein that may play a role in controlling melanosome growth and maturation. A number of mutations in the OA1 gene lead to ocular albinism due at least in part to retention of the aberrant protein in the endoplasmic reticulum. To examine whether N-glycosylation plays a role in the post-translational trafficking of the Oa1 protein, we constructed a series of mutant mouse Oa1 cDNAs encoding an Oa1-green fluorescent protein fusion in which some or all of the potential glycosylation sites were eliminated by site-directed mutagenesis. Biochemical studies in transfected cells treated with tunicamycin and peptide:N-glycosidase F suggest that asparagine at amino acid 106 is essential for N-glycosylation of the protein. Mutation at amino acid 106 that eliminated glycosylation did not affect the endo/lysosomal distribution of the Oa1 protein in either COS cells or cultured murine melanocytes.     

Dissolved Organic Carbon Leaching from a Coniferous Forest Floor -- A Field Manipulation Experiment

Leaching of dissolved organic carbon (DOC) from the O layer is important for the carbon cycling of forest soils. Here we study the role of the Oi, Oe and Oa horizons in DOC leaching from the forest floor in field manipulations carried out in a Norway spruce forest stand in southern Sweden. The manipulations involved the addition and removal of litter and the removal of Oi, Oe and Oa horizons. Our data suggest that both recent litter and humified organic matter contribute significantly to the leaching of dissolved organic matter from the O layer. An addition of litter corresponding to four times annual litterfall resulted in a 35% increase in DOC concentrations and fluxes although the specific UV absorbance remained unchanged. The removal of litterfall and the Oi horizon resulted in a decreased DOC concentration and in a significant increase in the molar UV absorptivity. The DOC concentration under the Oa horizon was not significantly different from that under the Oe horizon and there were no increase in DOC flux, but rather a decrease, from the bottom of the Oe horizon to the bottom of the Oa horizon, suggesting that there is no net release of DOC in the Oa horizon. However, significant leaching of DOC occurred from the Oa horizon when litterfall and the Oi and Oe horizons were removed. This indicates that there is both a removal of DOC from the Oi and Oe horizons and a substantial production of DOC in the Oa horizon. Quantitatively, we suggest that the Oi, Oe and Oa horizons contributed approximately 20, 30 and 50%, respectively, to the overall leaching of DOC from the O layer.     

The genera of Aphelinidae (Hymenoptera) of The world

Abstract A key is given to the world genera of the chalcidoid family Aphelinidae. Forty-four genera are accepted as valid, including three described as new, Encarsiella (type-species E.noyesi sp.n.), Hirtaphelinus (type-species H.smetanai sp.n.) and Samariola (type-species S.camerounensis sp.n.). The key is followed by a synopsis of the world genera, which includes: (1) citations of valid genera and their synonyms in chronological order; (2) total or approximate number of described species; (3) distribution in the six zoogeographical regions; (4) references mainly to major works and revisions; and (5) comments, especially on the new synonymies introduced in the present paper. The following new synonymies are proposed (the senior synonyms (valid names) are noted in parentheses): Aleurodiphilus DeBach & Rose ( Encarsia Foerster); Aneristus Howard, Ataneostigma Girault, Heptacritus De Santis ( Coccophagus Westwood); Artas Howard (Pteroptrix Westwood); Plastocharella Girault, Turmidiscapus Girault ( Centrodora Foerster); Encyrtophyscus Blanchard, Physculus Jasnosh, Physcus Howard ( Coccobius Ratzeburg); Mesidia Foerster ( Aphelinus Dalman); Paranthemus Girault ( Cales Howard); Primaprospaltella DeBach & LaSalle ( Coccophagoides Girault). The following genera are regarded as of doubtful position: Mesopirene Girault, Neocales Risbec, Paulianaphelinus Risbec and Verekia Risbec.     

The Ocular Albinism Type 1 Gene Product is an N‐Glycoprotein but Glycosylation is not Required for its Subcellular Distribution

The ocular albinism type 1 (OA1) gene product is a membrane glycoprotein that may play a role in controlling melanosome growth and maturation. A number of mutations in the OA1 gene lead to ocular albinism due at least in part to retention of the aberrant protein in the endoplasmic reticulum. To examine whether N‐glycosylation plays a role in the post‐translational trafficking of the Oa1 protein, we constructed a series of mutant mouse Oa1 cDNAs encoding an Oa1‐green fluorescent protein fusion in which some or all of the potential glycosylation sites were eliminated by site‐directed mutagenesis. Biochemical studies in transfected cells treated with tunicamycin and peptide:N‐glycosidase F suggest that asparagine at amino acid 106 is essential for N‐glycosylation of the protein. Mutation at amino acid 106 that eliminated glycosylation did not affect the endo/lysosomal distribution of the Oa1 protein in either COS cells or cultured murine melanocytes.     

Specific interaction of Gαi3 with the Oa1 G-protein coupled receptor controls the size and density of melanosomes in retinal pigment epithelium

Background

Ocular albinism type 1, an X-linked disease characterized by the presence of enlarged melanosomes in the retinal pigment epithelium (RPE) and abnormal crossing of axons at the optic chiasm, is caused by mutations in the OA1 gene. The protein product of this gene is a G-protein-coupled receptor (GPCR) localized in RPE melanosomes. The Oa1-/- mouse model of ocular albinism reproduces the human disease. Oa1 has been shown to immunoprecipitate with the Gαi subunit of heterotrimeric G proteins from human skin melanocytes. However, the Gαi subfamily has three highly homologous members, Gαi1, Gαi2 and Gαi3 and it is possible that one or more of them partners with Oa1. We had previously shown by in-vivo studies that Gαi3-/- and Oa1-/- mice have similar RPE phenotype and decussation patterns. In this paper we analyze the specificity of the Oa1-Gαi interaction.

Methodology

By using the genetic mouse models Gαi1-/-, Gαi2-/-, Gαi3-/- and the double knockout Gαi1-/-, Gαi3-/- that lack functional Gαi1, Gαi2, Gαi3, or both Gαi1 and Gαi3 proteins, respectively, we show that Gαi3 is critical for the maintenance of a normal melanosomal phenotype and that its absence is associated with changes in melanosomal size and density. GST-pull-down and immunoprecipitation assays conclusively demonstrate that Gαi3 is the only Gαi that binds to Oa1. Western blots show that Gαi3 expression is barely detectable in the Oa1-/- RPE, strongly supporting a previously unsuspected role for Gαi3 in melanosomal biogenesis.

Conclusion

Our results identify the Oa1 transducer Gαi3 as the first downstream component in the Oa1 signaling pathway.     

A new species of Arenaria subgenus Odontostemma from Tibet, with a review of the status of the genus Gooringia (Caryophyllaceae)

A specimen collected in southern Tibet in 1928, hitherto identified only as "Arenanu sp.", is found to represent a new species of the subgenus Odontostemma . The new species resembles A. littledalei , the species that forms the basis of the monotypic genus Gooringia , characterized by a dwarf habit, a tetramerous perianth and only two or three stamens. Several other species of Arenaria subgenus Odontostemma resemble A. littledalei in habit and one ( A. saginoides ) is tetramerous, but hitherto none has been found with its extremely reduced androecium. The new species has an identical androecium to A. littledalei and its discovery leaves no doubt that Gooringia should not be recognized taxonomically at any rank. The new species is described as A. pharensis McNcill & Majumdar and a table compares its diagnostic features with those of A. littledalei and five other dwarf Arenaria species of sibgrnus Odontostemma from the mountains of Sikkim, Tibet, Yunnan and Tsinghai.     

Calceolariaceae: floral development and systematic implications

The recent establishment of the new family Calceolariaceae, separated from Scrophulariaceae on the basis of molecular evidence, is complemented here by a scanning electron microscopy study of floral morphology and development of 12 species encompassing all genera (Calceolaria, Jovellana, and Stemotria [= Porodittia]). All species showed a similar pattern of organ initiation. The slightly zygomorphic, four-merous calyx is the first floral organ series initiated, with the primordia emerging consecutively in a unidirectional (dorso-ventral) succession. The two entire corolla lips in Calceolaria and Jovellana arise as uniform meristematic ridges (sometimes with a central emargination, especially in Jovellana), kept apart by two lateral stamen primordia. Later the margins of the lips fuse across the backs of the young stamens, giving rise to the short corolla tube (late sympetaly). Stemotria stands out by having three stamens instead of two and a bilobed lower lip, resulting in a trimerous corolla. Similar architecture was found in teratological flowers of Calceolaria. The perianth of Calceolariaceae is shown to be derived from a tetramerous condition, not from pentamery as traditionally believed. This is in agreement with the separation of Calceolariaceae from Scrophulariaceae and with their placement in succession of Oleaceae and Tetrachondraceae in the basal Lamiales. The hitherto puzzling molecular evidence is thus supported by morphological-developmental features of the flower.     

A new species of <Emphasis Type="Italic">Comocladia</Emphasis> (Anacardiaceae) from Belize and Guatemala

Comocladia mayana, a new species of Anacardiaceae, is described, mapped and illustrated. The species is endemic to western Belize and adjacent Guatemala and is restricted to semi-deciduous moist forest on karstic limestone formations. It differs from all other Comocladia species by the combination of entire to subentire, acuminate leaflets and tetramerous staminate flowers.     

Response of dissolved organic matter in the forest floor to long-term manipulation of litter and throughfall inputs

Dissolved organic matter (DOM) contributes to organic carbon either stored in mineral soil horizons or exported to the hydrosphere. However, the main controls of DOM dynamics are still under debate. We studied fresh leaf litter and more decomposed organic material as the main sources of DOM exported from the forest floor of a mixed beech/oak forest in Germany. In the field we doubled and excluded aboveground litter input and doubled the input of throughfall. From 1999 to 2005 we measured concentrations and fluxes of dissolved organic C and N (DOC, DON) beneath the Oi and Oe/Oa horizon. DOM composition was traced by UV and fluorescence spectroscopy. In selected DOM samples we analyzed the concentrations of phenols, pentoses and hexoses, and lignin-derived phenols by CuO oxidation. DOC and DON concentrations and fluxes almost doubled instantaneously in both horizons of the forest floor by doubling the litter input and DOC concentrations averaged 82 mg C l⁻¹ in the Oe/Oa horizon. Properties of DOM did not suggest a change of the main DOM source towards fresh litter. In turn, increasing ratios of hexoses to pentoses and a larger content of lignin-derived phenols in the Oe/Oa horizon of the Double litter plots in comparison to the Control plots indicated a priming effect: Addition of fresh litter stimulated microbial activity resulting in increased microbial production of DOM from organic material already stored in Oe/Oa horizons. Exclusion of litter input resulted in an immediate decrease in DOC concentrations and fluxes in the thin Oi horizon. In the Oe/Oa horizon DOC concentrations started to decline in the third year and were significantly smaller than those in the Control after 5 years. Properties of DOM indicated an increased proportion of microbially and throughfall derived compounds after exclusion of litter inputs. Dissolved organic N did not decrease upon litter exclusion. We assume a microbial transformation of mineral N from throughfall and N mineralization to DON. Increased amounts of throughfall resulted in almost equivalently increased DOC fluxes in the Oe/Oa horizon. However, long-term additional throughfall inputs resulted in significantly declining DOC concentrations over time. We conclude that DOM leaving the forest floor derives mainly from decomposed organic material stored in Oe/Oa horizons. Leaching of organic matter from fresh litter is of less importance. Observed effects of litter manipulations strongly depend on time and the stocks of organic matter in forest floor horizons. Long-term experiments are particularly necessary in soils/horizons with large stocks of organic matter and in studies focusing on effects of declined substrate availability. The expected increased primary production upon climate change with subsequently enhanced litter input may result in an increased production of DOM from organic soil horizons.     

<Emphasis Type="Italic">Apeiba trombetensis</Emphasis> (Malvaceae: Grewioideae), a new species from northern Brazil

Apeiba trombetensis is described from northern Brazil, illustrated, and distinguished from related species. It is remarkable for its tetramerous calyx, sepal pubescence, and its large, globose capsules with stout spines.     

Floral ontogeny in Passiflora lobata (Malpighiales,Passifloraceae) reveals a rare pattern in petal formation and provides new evidence for interpretation of the tendril and corona

Passiflora lobata differs from most other passion flowers in that it has a tetramerous gynoecium and dorsiventral flowers. A detailed ontogenetic analysis using scanning electron microscopy revealed the following characters: tendril formation starts late, indicating an axial nature. The paired flowers show mirror symmetry, which is manifested very early in ontogeny. Five sepals initiate in a spiral followed by five petals, which are formed successively adjacent to each other. This is a rare pattern and the first report in Passifloraceae. Frequently a sixth petal primordium was found, which never develops and which could be interpreted as the first outgrowth or frill of the corona (which therefore might be interpreted as derived from the perianth). The abaxial carpel forms always in front of the first-formed sepal. The remaining three carpels are alternate with the stamens. This means that a positional change took place from the typical trimerous ovary with two carpels in front of stamens to only one antestaminal carpel in P. lobata. This shift might have opened up space for a fourth carpel. Together with the analysis of other tetramerous Passifloraceae, this study will foster the understanding of flower morphology in this family and its systematic relationships among Malpighiales.     

Comparative floral ontogeny of Maesa (Maesaceae), Aegiceras (Myrsinaceae) and Embelia (Myrsinaceae): taxonomic and phylogenetic implications

The comparative floral ontogeny of five species belonging to the primuloid clade of the Ericales are investigated, viz. Maesa japonica, M. perlarius, Aegiceras corniculatum, Embelia laeta and E. ribes. All five species basically show 2/5-spiral phyllotaxis of the sepal primordia, although with some minor modification (particularly in Embelia, where the flowers are predominantly tetramerous). The phyllotaxis of the common petal-stamen primordia is also 2/5-spiral in the Maesa and Aegiceras species investigated, but appears to be unidirectional in Embelia. All five species develop common petal-stamen primordia in which the resultant petal primordia are larger than the stamen primordia, and in which the stamens develop proximally on the adaxial flank of the common primordia. Growth of the placenta in Maesa and Aegiceras partially embeds the ovules, but in Embelia the ovules are almost fully immersed in placental tissue at maturity. A comprehensive review of all previously published studies of floral ontogeny of primuloid genera is presented, and the phylogenetic significance of the variation between genera is evaluated with reference to recently published cladograms.